<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
<script>
    // 简单数据类型 BigInt()
    // 构造函数，代码可读性
    const wes = Symbol('Wes');
    const person = Symbol('Wes');
    // console.log(wes == person);
    const classRoom = {
        [Symbol('Mark')]:{grade:50,gender:'male'},
        [Symbol('oliva')]:{grade:80,gender:'female'},
        [Symbol('oliva')]:{grade:85,gender:'female'},
        "dl":["国文","陈倩文"]
    }
    // console.log(classRoom);
    // for key in
    // symbol key 不可以被枚举
    for (const person in classRoom){
        console.log(person,'////')
    }

    const syms = Object.getOwnPropertySymbols(classRoom);
    // console.log(syms);
    const data = syms.map(sym=>classRoom[sym]);
    console.log(data);
</script>
</body>
</html>